I'll add another issue since this topic is pinned.
When filing a tax for myself and spouse I found I can't use autofill for my spouse. For me it downloads the data fine (what little is currently available at CRA). However, when attempting to download for my spouse I get a message that the minimum details of SIN, Birthdate, Province of Residence, and Marital Status must be filled in. I assume this is because the Spouse's Identification page doesn't appear to have Martial Status field. Again I'm assuming this is because it's a combined return and the Martial Status question was answered on my Identification page.
Seems like an oversight, but I wonder how it wasn't caught.
So far Autofill is turning out to be more trouble than it's worth, but it would have been cool if it worked well!